• Journal of Biomedical Engineering Research
• /
• v.24 no.5
• /
• pp.459-464
• /
• 2003

The source current distribution in a heart was reconstructed from the magnetocardiogram (MCG) and its clinical usefulness was demonstrated. MCG was measured using 40-channel superconducting quantum interference device (SQUID) gradiometers for a patient of Wolff-Parkinson-White (WPW) syndrome, which has an accessory pathway between the atria and the ventricles. Reconstruction of source current distribution in a plane below the chest surface was performed using minimum norm estimation (MNE) algorithm and truncated singular value decomposition (SVD), In the simulation, we confirmed that the current distributions. which were computed for the test dipoles, represented well the essential feature of the test current configurations, In the current map of WPW syndrome, we observed abnormal currents that would bypass the atrioventricular junction at a delta wave. However, we could not observe such currents any more after the surgery. These results showed that the obtained current distribution using MCG signals is consistent with the electrical activity in a heart and has clinical usefulness.

• Journal of Veterinary Clinics
• /
• v.32 no.1
• /
• pp.5-8
• /
• 2015

D-dimer is a fibrin degradation product (FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis. D-dimer concentration is widely used for determining thrombosis and thromboembolism. Because one major cause of thromboembolism is congestive heart failure in human, we investigated the degree and risk of thromboembolism in dogs with different stage of congestive heart failure caused by chronic mitral valvular insufficiency (CMVI). The plasma level of d-dimer was evaluated in 20 healthy dogs and 30 dogs with different stage of congestive heart failure caused by CMVI. The d-dimer concentrations were measured by a commercialized assay kit. The plasma levels of d-dimer were not significantly different between healthy and CMVI dogs. Furthermore, there was no association of d-dimer concentrations to left atrium to aorta (LA/Ao) ratio, left ventricular dimension at diastole to aorta (LVIDd/Ao) ratio and severity of heart failure in our study population. Our study results implied that the degree of thromboembolism in canine heart failure might be minimal or the plasma d-dimer test might not be reliable for detecting thromboembolism in dogs.

• Journal of Chest Surgery
• /
• v.18 no.2
• /
• pp.193-204
• /
• 1985

During the period from February to March, 1984, we employed a partial left heart bypass [left atrium to ascending aorta] in 2 patients who could not weaned from cardiopulmonary bypass with inotropic agents and cardiac pacing after coronary bypass surgery. These two patients showed significant improvement in ventricular function 18 to 47 hours after inserting the left heart bypass and were able to wean from the left heart bypass under using inotropic agents. Two patients died of multiple organ failures 11 days and 15 days postoperatively. These results indicate that early institution of left heart bypass in ventricular failure patients after open heart surgery can provide satisfactory long-term result.

• Journal of Veterinary Clinics
• /
• v.32 no.2
• /
• pp.162-167
• /
• 2015

Tei-index has been reported as one of reliable echocardiographic factors for evaluating cardiac function in human and small animals. In this study, Tei-index were measured and evaluated with other echocardiographic parameters in normal thirteen beagle dogs and thirty-one dogs with mitral valve degeneration. Normal range of Tei index with tissue Doppler obtained at septum and left ventricular free wall was $0.58{\pm}0.07$ and $0.60{\pm}0.07$, respectively. The values between septum and left ventricular free wall did not show significant difference. Tissue Doppler derived tei index showed better reproducibility and significantly lower values than the results obtained by pulsed wave Doppler. Tei index obtained in either method increased with the progression of clinical signs. Therefore, the increase of Tei index in dogs with mitral regurgitation is thought to be an useful factor reflecting left ventricular dysfunction.

• Journal of Chest Surgery
• /
• v.38 no.5 s.250
• /
• pp.357-365
• /
• 2005

Background: Patients with mitral regurgitation (MR) in the setting of coronary artery disease have a dismal long-term prognosis whether treated medically or surgically. Moreover, the optimal management of moderate ischemic MR at the time of coronary artery bypass grafting (CABG) remains the subjects of controversy. Thus, the present retrospective study was undertaken to determine whether mitral valve surgery for moderate ischemic MR at the time of CABG would be preferable to CABG alone in terms of clinical outcome. Material and Method: Between January 1997 and December 2003, 34 patients with moderate (Gr 3/4) ischemic MR underwent CABG alone (Group I, n=23) or CABG plus mitral valve surgery (Group II, n=11). Operative mortality, long-term survival and echocardiographic parameters were used to evaluate the efficacy of mitral valve surgery in patients with moderate ischemic MR. The mean follow-up durations of each group were $69.3\pm4.3$ months and $53.1\pm4.9$ months respectively. Result: There was no hospital mortality in both groups. There was one case of late mortality in Group I. The mean number of bypass graft was similar ($3.8\pm1.2\;vs\;3.7\pm1.3$ respectively). Cardiopulmonary bypass time was longer in group II (p=0.014). In group II, all of the patients received mitral annuloplasty using ring. On immediate postoperative echo-cardiogram, mitral regurgitation was reduced more in group II (p=0.002). Echocardiogram performed at last follow-up state showed no difference except the grade of MR between the two groups. Actuarial survival of both groups at 5 years was similar ($95.5\%\;vs\;100\%$, p=0.48). Conclusion: This study shows that in selected patients with moderate ischemic MR, CABG without mitral valve surgery might be sufficient. However, patients with low EF and NYHA functional class pre-operatively had tendency of significant residual MR, so mitral valve surgery should be necessary in these patients, and moreover, MR severity and left ventricle volume decreased more in mitral valve surgery group. Therefore, more large-scale studies are necessary to determine these effects on the ventricular function and long-term survival.

• Journal of Chest Surgery
• /
• v.39 no.3 s.260
• /
• pp.184-193
• /
• 2006

Background: Off-pump coronary artery bypass grafting (OPCAB) has been proven to result in less morbidity. The patients who have left ventricular dysfunction may have benefits by avoiding the adverse effects of the cardiopulmonary bypass. The present study compared early and midterm outcomes of off-pump versus on-pump coronary artery bypass grafting (On pump CABG) in patients with severe left ventricular dysfunction. Material and Method: Ninety hundred forth six patients underwent isolated coronary artery bypass grafting by one surgeon between January 2001 and Febrary 2005.. Data were collected in 100 patients who had left ventricular ejection fraction (L VEF) less than $35\%$ (68 OPCAB; 32 On pump CABG). Mean age of patients were 62.9$\pm$9.0 years in OPCAS group and 63.8$\pm$8.0 years in On pump CABG group. We compared the preoperative risk factors and evaluated early and midterm outcomes. Result: In OPCAB and On pump CABG group, mean number of used grafts per patient were 2.75$\pm$0.72, 2.78$\pm$0.55 and mean number of distal anastomoses were 3.00$\pm$0.79, 3.16$\pm$0.72 respectively. There was one perioperative death in OPCAB group ($1.5\%$). The operation time, ventilation time, ICU stay time, CK-MB on the first postoperative day, and occurrence rate of complications were significantly low in OPCAB group. Mean follow-up time was 26.6$\pm$12.8 months (4${\~}$54 months). Mean LVEF of OPCAB and On pump CABG group improved significantly from $27.1\pm4.5\%$ to $40.7\pm13.0\%$ and $26.9\pm5.4\%$ to $33.3\pm13.7\%$. The 4-year actuarial survival rate of OPCAB and On pump CABG group were $92.2\%,\;88.3\%$ and the 4-year freedom rates from cardiac death were $97.7\%,\;96.4\%$ respectively. There were no significant differences between two groups in 4 year freedom rate from cardiac event and angina. Conclusion: OPCAS improves myocardial function and favors early and mid-term outcomes in patients with severe left ventricular dysfunction compared to On pump CABG group. Therefore, OPCAB is a preferable operative strategy even in patients with severe left ventricular dysfunction.

• Clinical and Experimental Pediatrics
• /
• v.52 no.8
• /
• pp.910-916
• /
• 2009

Purpose : The arterial switch operation (ASO) has become the preferred procedure for the surgical management of transposition of the great arteries (TGA). We conducted a retrospective evaluation of our experience in 30 patients seen from January 2003 to July 2008, in order to determine outcomes and related risk factors after the arterial switch operation. Methods : Patients charts, surgical reports, and echocardiograms were retrospectively reviewed. And they were analyzed in 2 different groups: complex (n=16) versus simple TGAs (n=14). Complex TGAs are TGAs with VSD or the Taussig-Bing anomaly with or without aortic arch anomalies. Simple TGAs are defined as TGAs with intact ventricular septum having no such anomalies. Median follow-up time was 44 months (3-63 months). Results : Hospital mortality was 0%. However, follow-up echocardiographies revealed potential complications, including stenosis of the branch pulmonary arteries, neo-aortic and/or neo-pulmonary valvar regurgitation, and right or left ventricular outflow tract obstructions. Great arterial relationship (side-by-side), association of aortic arch anomalies, and the existence of the Taussig- Bing anomaly were assessed as significant risk factors of neo-aortic and/or neo-pulmonary valvar regurgitation in this series. On the other hand, right or left ventricular outflow tract obstructions were more frequently found in patients demonstrating VSD, side-by-side positioned great arteries, or associated coronary anomalies. Conclusion : The ASO is the procedure of choice in the treatment of TGA. However, special attention and follow-ups are needed to detect residual problems like the stenosis of the branch pulmonary arteries, neo-aortic and/or neo-pulmonary valvar regurgitation, as well as ventricular outflow tract obstructions.

• Journal of Chest Surgery
• /
• v.42 no.5
• /
• pp.630-634
• /
• 2009

According to the 2007 International Society for Heart and Lung Transplantation (ISHLT) report, a congenital diagnosis, infantile transplantation and being on extracorporeal membrane oxygenation (ECMO) at the time of transplant are risk factors for mortality for the patients who undergo a heart transplant, and a large body weight ratio also increases the risk of mortality. The patient of this case underwent a Ross operation and mitral valve repair due to left ventricle outflow track obstruction and mitral regurgitation. But the baby was treated with ECMO due to heart failure after the operation. When he was 3-months-old and had been. on 30 days of ECMO, he underwent a heart transplant with a heart that had a high donor-recipient weight ratio (4.42). We present this case from a technical standpoint and we include a review of the relevant literature.

• Journal of Chest Surgery
• /
• v.30 no.4
• /
• pp.383-389
• /
• 1997

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60$\pm$5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class 111 in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4$\pm$4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 $\pm$8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5$\pm$ 1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 $\pm$ 13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.

• Journal of Chest Surgery
• /
• v.43 no.1
• /
• pp.63-66
• /
• 2010

Apical muscular ventricular septal defects (VSDs) are relatively rare conditions among all the different types of VSDs. Apical VSDs are difficult to treat because of they are difficult to visualize through a trans-atrioventricular approach, and especially in infants. Treatment by left ventriculotomy is associated with long-term ventricular dysfunction. Catheter-based intervention still shows less than satisfactory results and this type of intervention may not be possible in small infants. This report describes the benefits of right apical ventriculotomy in terms of successful closure of the lesion without harming the ventricular function.